Apparatus for coiling compound torsion springs



July 2, 1935. F, FUCHS 2,006,389

APPARATUS FOR COILING COMPOUND TORSION SPRINGS Filed Sept. 8, 1955 wry Patented July 2, 1935 I UNI-TED STAT Y APPARATUS FOR COILING COMPOUND TORSION SPRINGS Friedrich Fuchs, Leitmeritz, Czechoslovakia Application SeptemberS, 1933, Serial No. 688,602

I In Czechoslovakia October-24,1932

8 Claims (oil 153- 65) This invention relates to a coiling device for the production of so-called stepped or com--' pound torsion springs, composed. of a plurality of coaxially disposed spiral springs of differentdiameters. This device enables the springs to be made economically and independent of human skill. The material is fed by means of a rolling mill, in' known manner, and according to the presentfiinvention, to a shaping jaw, which coils the material in sucha manner. as to produce-a predetermined diameter and an accurate pitch according to the type and arrangement of the jaw. If now, various jaws of this kind bemounted on a turntable adapted to revolve like a turret, so that, in'each case, oneoi said jaws. is brought into position facing the mouth of the rolling mill, the stepped-torsion spring can be coiled from a single strip. In so doing,-the material is forced successively against the jaws of different sizes,which impart the corresponding diameter and pitch to the 'strip,without demanding any special preliminary .knowledgeflin the working of the apparatus. The manipulation is confined to feeding the materiaLnwith the. aid of the rolling mill, to the smallest jaw in the first place, thus coiling the inmost spring, then turning the turret until the next larger jaw is in the working position, rolling the intermediate spiral spring, and so on, until the entire spring is completed. I

In order more clearly to'understand the invention, reference is made to the accompanying drawing, which illustrates diagrammatical ly and by way of example, one embodiment thereof, and in which: i V

Fig. 1 is an elevation, partly in section, of the rolling mill and shaping jaws on a turntable;

Fig. 2 is a plan view of the apparatus illustrated in Fig. 1;

Fig. 3 is a detail of a compound spring, in vertical section, and produced in the apparatus of the present invention;

Figure 4 is a plan view of Figure 3; 7

Figures 5, 7 and 9 are details in end elevational of three shaping jaws; and

Figures 6, 8 and 10 respectively, are corresponding side elevations. Y

The material is fed, by the rolling mill, with the two rollers a, through a tapered mouth, into contact with the jaws d, e, or f. The rollers are positively driven by the two pinions I, so that v the material is reliably fed by turning a crank.

Each of the jaws is shaped and disposed in a manhercorrespohding to the desired diameter and. pitchof the spring.

The jaws d, e, f, for shaping the springs'are semicylindrically recessed. Owing to the elasticity'of the strip material, the radius of the semi cylinder is slightly less than the radius of the spring to be coiled. The jaws are located on such a .level that the strip material, which'is fed from the rolling .mill to the jaws, enters the latter exactlypna level with. the lower edge of the semicylindrical recess. In order to facilitate -'-guiding' the strip into the jaws, especially in the case of the larger jaws, the semicylindrical recess is chamfered at its lower edge. In correspondence withfthe pitch of the threads, the jaws are mounted on the "turretuat a suitable angle, instead of radially. In order positively to guide the springs, the jaws are provided, at the exit side, with small steelv plates between which the coiled strip is guided. The two auxiliary jaws m and'n, which" eifectthe transition from'o'ne type of helix to anothenareof similar design, but these do not require any lateral Iguide plate, since they have. only. to' shape halfa turn of thethreadp, Ihe rolling mill is fitted with a dividing plate 7' and pointer is, which'serve' for counting the turns of the several springs. The turret g is provided with notches and a pawl h which, in each case, is caused, by means of a spring 11, to engage in the notch locking the jaw in working position in relation to the rolling mill. The turret g is centered in a baseplate, by means of a pedestal g,

' in known manner.

The operation of coiling is performed in the following manner:

The material 0 is inserted in the taper mouth,

and the rolls a, are turned by a crank'and the pinions I, so that the strip runs along the hardened jaw d and is thereby coiled to form a spiral spring. The number of turns is read off on the dividing plate 7', and when the desired number is attained, the work is interrupted for the time being. The pawl'h is swung out and the turret with equal success, by any other device serving to bringthe jaws into position facing the taper: mouth of the rolling'mill. According to the present invention, in order to simplify bringing the concentrically disposed springs into coaxial position, auxiliary jaws m and n, against which the material is advanced by the distance of half a thread, are provided between each successive pair of jaws. In this manner a gradual transition from one diameter to the other is obtained. Externally, the auxiliary jaws have the same form as the shaping jaws, but are not provided with a pitch-forming device. The preparation for reversing the (for example) left-handed thread into the right-handed thread is effected in the auxiliary jaws.

I claim:

1. In an apparatus for coaxially coiling compound torsion springs, a plurality of shaping jaws having segmental cylindrical concave surfaces of progressively different diameters and formed with screw threads alternately of opposite pitch, means for feeding strip material against said jaws, and means for bringing said surfaces of said jaws successively opposite said strip feeding means.

2. In an apparatus for coaxially coiling compound torsion springs, a plurality of shaping jaws having segmental cylindrical concave surfaces of progressively difierent diameters and formed with screw threads alternately of opposite pitch, a plurality of auxiliary jaws having concave surfaces transitional from one said diameter to another interspaced between said shaping jaws, means for feeding strip material against said jaws, and means for bringing said surfaces of said jaws successively opposite said strip feeding means.

31.. In an apparatus for coaxially coiling compound torsion springs, a plurality of shaping jaws rality of auxiliary jaws having concave surface transitional from one said diameter to another interspaced between said shaping jaws, means for feeding strip material against said jaws, and a rotatable turret on which said jaws are mounted opposite said strip feeding means.

5. In an apparatus for coaxially coiling compound torsion springs, a plurality of shaping jaws having segmental cylindrical concave surfaces of progressively different diameters and formed with screw threads alternately of opposite pitch, rolls forfeeding strip material against said jaws, and. means for bringing said surfaces of said jaws successively opposite said rolls 6. In an apparatus for coaxially coiling compound torsion springs, a plurality of shaping jaws having segmental cylindrical concave surfaces of progressively different diameters and formed with screw threads alternately of opposite pitch, a plurality of auxiliary jaws having concave surfaces transitional from one said diameter to another interspaced between said shaping jaws, rolls for feeding strip material against said jaws, and

means for bringing said surfaces of said jaws successively opposite said rolls.

'7. In an apparatus for coaxially coiling compound torsion springs, a plurality of shaping jaws having segmental cylindrical concave surfaces of progressively different diameters and formed with screw threads alternately of opposite pitch, rolls for feeding strip material against said jaws, and

av rotatable turret on which said jaws are mounted opposite said rolls.

8. In an apparatus for coaxially coiling compound torsion springs, a plurality of shaping jaws- 

